Currently, there is provided a wireless road charge reception system including a vehicle detector that is provided to a road side strip that performs detection of a vehicle that passes through a road, and a road side antenna that performs a radio communication with the an in-vehicle device that is mounted on a vehicle that passes through the vehicle detector. The wireless road charge reception system has a mechanism in which a vehicle is specified by regarding a vehicle that is detected by the vehicle detector and a vehicle that performs a radio communication are regarded as the same vehicle, and charging is performed with respect to the vehicle that is specified.
In the current wireless road charge reception system, a communication between the antenna and the in-vehicle device is performed in a dedicated short range communications (DSRC) type, and in a next generation wireless road charge reception system, a radio communication type called wave (IEEE802.11p) is scheduled to be employed. The DSRC type corresponds to a communication with a single carrier wave, but a wave type is an orthogonal frequency-division multiplexing (OFDM) type in which a plurality of carrier waves are multiplexed.
Furthermore, PTL 1 discloses a method of securing communication quality by calculating an arrival angle of a communication radio wave in the OFDM type, and by matching a main lobe of an antenna to the angle.